"There has been a little bit of surprise at the lack of resistance, particularly in areas where we anticipated meeting the Republican Guard," Group Captain Al Lockwood told Sky News from Qatar.

"That said it does show that possibly our air campaign has been very effective.

"Maybe large amounts of the Republican Guard have actually seen common sense and realised the regime's unsupportable and have gone home.

"But then again the option is they maybe have melted into the city of Baghdad itself and we could very well face slightly different attacks in the future," he added.

US troops rode tanks deep into the capital on Saturday, reportedly killing 1,000 Iraqi troops and claiming they could come and go as they pleased.

Lockwood said the incursion was "an American style of patrolling, sending the forces into Baghdad, reaching out, seeing what sort of opposition they faced and then returning back to report.

"It proved to be a very successful foray into Baghdad and did show there is support on the ground from the local people for the coalition forces."

But he was unable to shed any light on the fate of Ali Hassan al-Majid, a top aide to Iraqi President Saddam Hussein, after the US-led coalition said Saturday it had bombed his residence in the southern city of Basra.

Al-Majid is known as "Chemical Ali" for the ruthless campaign he waged against the Kurds at the end of the 1980-88 Iran-Iraq war.

"Obviously he's been one of the key targets but as to his actual whereabouts we have no idea at the moment," Lockwood said.

SPACE.WIRE